At this point of technical development,
current classically-trained string players use vibrato in every style and
passage of music for better or worse. This constant application of vibrato
became standard through the playing and teaching of great late nineteenth-
and early twentieth-century artists like violinist Leopold Auer and cellist
Pablo Casals. Today, the continuous vibrating of pitch by string players
in Baroque- and Classical-era music produces romanticized renditions against
which performance-practice advocates often shy away from in stylistic horror.
What all of this means for anyone writing music for violin, viola, cello,
or bass in these years preceding the new millennium is that they should
expect string parts to be rendered with oscillations of pitch emulating
the singing style of vocalists.
Before discussing the latest contemporary
and radically new applications in vibrato, a more specific understanding
of the traditional technique is warranted. First, vibrato is usually a
uniform oscillating of pitch with two variables - speed and distance. Different
combinations of an oscillation's speed and its distance produce a variety
of sound colors. Johannes Brahms used in his music the Italian terms espressivo
and dolce which, among other things, imply different kinds of vibrato.
Generally, espressivo implies a vibrato oscillation that is relatively
fast and narrow. On the other hand, dolce vibrato is executed relatively
slowly and widely, for which such descriptive adjectives as sweet and warm
apply. Another important basic concept to understand about vibrato is that
it occurs only below the pitch. The human ear is very biased toward higher
frequencies and hears the top crests as the true pitch rather than any
median point in the middle of the oscillation waves.
concepts are the basis of departure for more unique and contemporary vibrato
Now to the heart of the vibrant matter, the first major alternative to
the omnipresence of oscillating string pitches which contemporary writers
often use is to stipulate that the music be played without any vibrato
whatsoever. This is communicated rhetorically at the beginning of a score
or in performance notes, or with such expressions above the staff as senza
vibrato or no vib if just a section, phrase, or even particular note is
to sound as a white tone, straight without vibrato. To avoid confusion,
if a player sees an indication above the staff to turn off vibrato, then
that player needs to know when to turn it back on as communicated with
some such expressions as con vibrato or vib. It is analogous to modern
lighting - if one wishes to see in the dark again after the lights have
been turned off, one must turn the switch on again.
To play a string instrument
without vibrato causes a drastic change in tonal color. The Kronos Quartet
uses no vibrato in much of their minimalist repertoire. The purity of harmonic
intervals they create without vibrating produces one of the great, characteristic
sounds of their ensemble. Also, many times vibrato is withheld in microtonal
works where oscillating pitches would compromise the audible integrity
of an alternative tuning. Likewise, in compositions where there are a lot
of glissandi or sliding between and bending of pitches, vibrato is often
not used because it tends to obscure the moving off of and onto true pitches.
As a point of moderation, composers are now
sometimes asking for something called poco vibrato which strikes a medium
between obvious oscillating pitch and stark, straight pitch. Poco vibrato
is a discreet oscillation of the most narrow distance and of a not overly
rapid speed. Of course, gradual changes from nonvibrato to poco vibrato
to espressivo, sometimes called molto vibrato, and in the reverse order
can be executed over the course of a passage or even within one note.
When oscillations are pushed beyond molto vibrato,
string playing enters a radical land of instrumental techniques. All of
these so-called extended vibrato techniques when they are used in a piece
need a concise explanation of their execution in the work's performance
notes. The term hypervibrato might well describe what happens when pitch
oscillations become extraordinarily fast or wide. A super fast oscillation
creates a tone reminiscent of a nanny goat's bray. Shaking the finger and
hand an overly wide distance of a half step or even a whole step makes
for a tone similar to the wah-wah effects in Jimi Hendrix's guitar playing.
To indicate these, the writer can use the expression hypervibrato above
the staff or use a graphic indication with the notes like Matthew Burrier
does in II for solo cello. This graphic representation of the vibrato allows
the player to follow the direction and contour suggested for the vibrato.
The graphic squiggles and lines can then further introduce irregular vibrato
oscillations and connect directly into and out of glissandos.
Lewis Nielson uses the interesting rhetorical
expression grotesque vibrato in the cello part of Valentine Mechanique
(Eating Carmen) for amplified cello and percussion. This indication removes
the uniform quality of the oscillation and produces spasmodic sounds of
unfocused pitches which in the context of Valentine Mechanique yields a
somewhat humorous caricature effect.
Vibrato can also be added to a glissando by
placing a rhetorical comment above the staff - vibrate while sliding between
pitches. This makes for a truly wild and hairy projecting sonic highlight
to the glissando.
Both traditional and radical vibratos are incorporated
with other instrumental techniques. Vibrato is used when playing pizzicato
(when the string is plucked or strummed with a finger). However, due to
the decaying acoustic nature of a plucked string, vibrato applications
tend to be somewhat less dramatic or acoustically obvious when played pizzicato
as opposed to when played with a bow. Artificial harmonics can also be
played with all the different types of vibrato. While it seems to be the
general order of composers today for artificial or false harmonics to be
rendered without vibrating, all one has to do is listen to a Paganini violin
concerto and hear the singing quality imparted to false harmonics executed
with vibrato to know the alternative. Usually it is left to the performerÕs
discretion as to whether or not to oscillate on artificial harmonics. If
a writer today definitely wishes to have artificial harmonics rendered
with a singing quality or some other wild alternative oscillation as opposed
to a straight tone that sounds somewhat like a pure sine wave, then a rhetorical
expression such as con vibrato or molto vibrato should be used above the
staff. For the natural harmonics on the open strings vibrato is hardly
ever used. Its application on the overtone nodes of the open strings produces
a phasing out of and into the focused pitch of the harmonic.
Extended vibrato techniques create new and
incredibly unique voicing for stringed instrument lines. There remains
more to discover about the sonic signatures vibrato imparts to a pitch,
and it is important to remember that the oscillating parameters of speed
and distance are what contemporary writers can manipulate to help customize
the sounds of vibrating wires.